Idempotency

// signBody(): see the Signature Generation Guide
async function createOrderWithRetry(order, idempotencyKey, maxAttempts = 4) {
  // Sign once: every attempt sends the same body and the same key
  const body = JSON.stringify({ ...order, signature: signBody(order, process.env.C2C_SIGNING_SECRET) });

  for (let attempt = 1; attempt <= maxAttempts; attempt++) {
    let response;
    try {
      response = await fetch(`${BASE_URL}/api/merchant/orders`, {
        method: 'POST',
        headers: {
          'C2C-API-Key': process.env.C2C_API_KEY,
          'Content-Type': 'application/json',
          'Idempotency-Key': idempotencyKey,   // same key on every attempt
        },
        body,
        signal: AbortSignal.timeout(15000),
      });
    } catch {
      response = null; // network error or timeout → the order may or may not exist; retrying is safe
    }

    if (response?.ok) return (await response.json()).data;
    if (response && response.status < 500) {
      throw new Error(`Not retryable: HTTP ${response.status} ${await response.text()}`);
    }
    await new Promise((r) => setTimeout(r, 2 ** attempt * 1000));
  }
  throw new Error('Order creation still failing after retries. Retry later with the same Idempotency-Key.');
}

import os, time, requests

# sign_body(): see the Signature Generation Guide
def create_order_with_retry(order: dict, idempotency_key: str, max_attempts: int = 4) -> dict:
    # Sign once: every attempt sends the same body and the same key
    body = {**order, "signature": sign_body(order, os.environ["C2C_SIGNING_SECRET"])}
    for attempt in range(1, max_attempts + 1):
        try:
            response = requests.post(
                f"{BASE_URL}/api/merchant/orders",
                json=body,
                headers={
                    "C2C-API-Key": os.environ["C2C_API_KEY"],
                    "Idempotency-Key": idempotency_key,   # same key on every attempt
                },
                timeout=15,
            )
        except requests.RequestException:
            response = None

        if response is not None and response.ok:
            return response.json()["data"]
        if response is not None and response.status_code < 500:
            raise RuntimeError(f"Not retryable: HTTP {response.status_code} {response.text}")
        time.sleep(2 ** attempt)
    raise RuntimeError("Still failing; retry later with the same Idempotency-Key.")